Graham AGKLOADED
Twig is a very very complex subject and not really for the beginner
http://twig.sensiolabs.org/doc/1.x/templates.html
is the manual for twig (there are a few restricted functions)
creating the actual twig file is the only easy part
first create a folder called _xtgem_templates in the main filebrowser
then upload this file (by url) to that folder http://syntax.xtgem.com/_templates/xtgem_blog.twig.js then rename the file xtblog.twig
That is the only bit that is easy
you will not see any changes in the blog as this is the standard file and it produces the standard blog
(once you actually create some posts as your blog is empty)
I will have a go at creating a 'latest posts' twig later